1. Field
Circuit Fabrication.
2. Background
The scribe process is used to scribe a circuit substrate (e.g., wafer) prior to sawing the substrate into individual chip or die. According to current technology, a scribe process often uses an ultraviolet laser (typically a yttrium aluminum garnet (YAG) laser) to scribe the substrate prior to a sawing operation. By scribing the substrate prior to sawing, a saw process that saws or cuts through the scribe area to divide or singulate the substrate can generally do so without damaging films (typically dielectric films) on the substrate. During a scribe process, the scribe is created in designated areas or streets by ablating any metal layers or dielectric layers (e.g., low dielectric constant dielectric layers) to the substrate (e.g., a silicon substrate). A laser scribe process typically generates ablated material (mostly silicon with some carbon) as debris. This debris tends to fall on the surface of the substrate. The surface of a substrate generally has a number of exposed contacts (e.g., bump contacts) on its surface. Thus, the debris tends to fall on the contacts and can adhere to the contact surface. This contamination of the contact surface inhibits the contacts from joining subsequent contacts during packaging leading to a characterization referred to as non-wet defects.